At the present time, digitizers and oscilloscopes are being developed essentially by increasing the acquisition pass band, in particular to satisfy telecommunication needs. This increase usually takes place at the detriment of the measurement dynamic range. Thus, an oscilloscope with a pass band of 6 GHz only has an effective dynamic range of 3.5 bits, namely about 11.
It then becomes impossible to measure a signal with a dynamic range greater than the dynamic range of an oscilloscope with sufficient precision (signal to noise ratio), on the same input and the same rated capacity of this oscilloscope.
The device for breaking down the dynamic range according to this invention can overcome such a lack of dynamic range.
When associated with a simple detector, this device can reconstitute an optical pulse with a large dynamic range, for example 3000 or more, by breaking this pulse down into several parts.
Consequently, all other performances of the measurement system, particularly the pass band, and a sufficient measurement precision in terms of metrology are maintained. Furthermore, the device makes it possible to easily reconstitute the pulse envelope because each part of this pulse is described by the same transfer function.
Various devices are already known for increasing the measurement dynamic range by breaking down the optical signal to be measured. But all these known devices are based on an electrical breakdown:                either they use a photo detector and breakdown the electrical signal provided by this photo detector using T separators,        or they breakdown the optical signal and use several photo detectors.        
The major disadvantage of these known devices lies in the fact that they require that a signal filtered by different transfer functions has to be reconstituted, since they use several channels of a digitizer or an oscilloscope and possibly several photo detectors.
Furthermore, when breaking down a dynamic range using an electrical device, the use of very long electrical cables degrades the time performances of the acquisition system.
Therefore, it is very difficult to reconstitute the optical signal and the performances achieved on the global template of the signal are limited.